The use of optical frequencies for telecommunications and other data processing applications has given rise to a need for optical devices which generate and/or modify and/or control signals at optical frequencies. Such devices include optical components, i.e. active and/or passive components. Examples of active components include signal generators, modulators, demodulators and amplifiers. A secondary harmonic generator is an example of a passive component. In addition to the optical components a device often includes electrical components for controlling the active optical components, connectors for both optical and electrical signals and substrates for supporting the other items.
Recent developments have provided these devices wherein the optical components are single crystals with suitable properties, e.g. U.S. Pat. No. 4,199,698 relates to the use of single crystals of 2-methyl-4-nitroaniline in non-linear devices.
It will be appreciated that there is widespread use of devices based on compositions having favourable non-linear properties. This invention relates to a new category of such materials.
According to this invention a composition with non-linear optical properties contains a vinylidene fluoride polymer and an additive having molecular non-linear optical activity.